Concrete reinforcement.



G. C. ROYSE.

CONCRETE REINFORCEMENT.

AIPLIOATION FILED SEPT. 20, 1912,

Patented Sept. 23, 1913.

ATTORNEYS nndulllu Q 1 WITNESSES "1TH ST a ENT F CONCRETE REINFORCEMENT.

Specification of Letters Patent.

Application filed September 20, 1912.

Patented Sept. 23, 1913.

Serial No. 721,423.

To all whom it may concern:

Be it known that I, Gnovnu C. Roysn, a citizen of the United States, and a resident of Tacoma, in the county of Pierce and State of Washington, have invented a new and useful Improvement in Concrete Reinforcements, of which the following is a specification.

My invention is an improvement in a system of concrete girder reinforcement, and has for its object the provision in a system of the character specified, of means for bracing the girder in such manner as to provide; the maximum resistance with a minimum of i metal, and so arranged that the distribution of the metal is in accordance with the direction of the stresses.

In the drawings:-Figure 1 is a partiall perspective view of the improved system,? Fig. 2 is a front View of the girder with; the reinforcement in place and with the concrete removed at one end of the girder, Figs. 3 and {l are sections on the lines 33 and 4-1 respectively of Fig. 2, and Fig. 5 is a transverse section of a modified form of construction. l

The present embodiment of the invention consists of a three bulbed, rolled, steel sec tion or bar, and a web which is divided into four parts, the sectional area of each of the parts being the same. The central bulb 1 is square in cross section, while the lateral bulbs 2 are round in cross section, and each of the lateral bulbs is connected to the central bulb by a portion 3 of the web, the other portions -1 of the web being at the outer sides of the bulbs 2. One object of the web is to connect the square or central bulb or bar to the outer round bulbs or bars, and the entire reinforcement is rolled in such shape that were a. line passed through the center of each web section, every point in this line will lie in the same horizontal plane. The metal comprising the reinforce- Inent section is so distributed that the cross section of the square bar and the two webs adjoining or lying alongside the said central bar is equal to the aggregate cross section of the two round bars and the 0utermost webs. This. arrangement permits the lateral bars and the webs lying outside of the said bars to be separated and displaced upward above the level of the central bar at the ends of the girder, without increasing or diminishing the total amount of metal at any particular point in the length of the reinforce! ncn t.

In order to provide aresistanceagainst the various stresses occurring in different parts of the girder, the rcin'lorcculent metal is treated as follows. The portion 3 of the web thatconnects tlurccntral bar 1 with the lateral bars 2 is sheared or out along the inner side of the bars 2 for a distance of approximately one-fourth the length of the girder from each end, thus permitting the outer end portions 2 of each of the bars 2 to be bent upward at an angle to the central portion. The extremities 2" of each of the said portions is then bent approximately horizontal with the portion 2 of the said bars. l Vhcn bent in this manner there is an equal amount of metal at the top and at the bottom of the girder. That portion 3 of the web which joins the rolmdbars 2 with the square bar 1 is punched through at intervals, and sheared along the bars for certain distances, and then bent upward as shown at 3, to form prongs .or spurs. Those portions 41: of the web that lie outside the lateral bars 2 are also cut to form prongs 4L that are bent upward with respect to the plane of the reinfor-cement and other prongs 41:" that are bent downward with respect to the portions 2 and 2 of the round bars. The prongs or spurs 4 are at the central portion of the girder, while the prongs or spurs 4* are at the end portions. At each extremity of bar 1, the web portions 3 are cut and bent dowmvardlv to form prongs or spurs 3'. Each of the said prongs 3, 3 and 4 is bent at an angle of 45 degrees, and it will be noted that the said prongs or spurs 3 and l are of such length that their ends overlap as shown more particularly in Fig. 2.

The above described arrangement pro vides a resistance for the shear, which in a uniformly loaded beam or girder is greatest at the supports, and decreases toward the center at which point it is zero. At this point however, the bending moment is greatest, and it is here that the girdcrwould break if there were not sufficient metal in the lower portion of the girder to resist the tension coming upon it, or if there were not enough resistance to compression in the upper part. Since the concrete 5 above the neutral axis is supposed to resist the compression, the tension is left for the steel of the reinforcement For this reason the on tire section of the bar is left intact for a distance of about one-fourth the length of the girder on each side of the center as clearly shown at 6 in Figs. 1 and 2, except that the web portions 3 are perforated or punched at intervals as shown at 7 thus forming a bond for the concrete.

W hen the requirements of the case demand that a wooden stringer 8 be supported on the under side of the beam or girder, the said support is connected to the reinforcement by means of holding devices. Each of the said devices consists of a strap 9, whose width is not greater than the length of the openings? Each of the said straps is provided at oneend with a tongue 10, and at the other with a slot or recess 11 for receiving the tongue, and the said strap is bent into the form of a loop which embraces the bar 1, the tongue 10 being received within the recess 11, and that portion of the strap opposite the tongue is provided with an opening for receiving a bolt 12. The bolt should be of sufficient length to eX- tend through a washer 18 and the stringer 8, and the lower end of the bolt is engaged by a nut 14 below the stringer, the said stringer being counter-sunk at 15 around the bolt to receive the nut. The strap arranged as specified, permits it to be clenched over the bar 1 and the washer 13 is of such size that it will space the bar 1 a sufficient distance above the stringer 8, thus holding the reinforcing metal the required distance from the bottom line of the concrete girder. In addition to its function of supporting the stringer, the holding devices above described, may be used to hold the form' in place during the time required for the concrete to set.

It will be evident that with the improved reinforcement all of the metal used in the girder is in one piece, thus constituting a strictly unit system. On account of the fact that the metal is all in one piece, it is easily and quickly placed and retains its proper shape, and the rolled bar is so treated that every stress in the girder is resisted by the bar. The portions 2" and 2 of the system support the central portion of the reinforcement, the free ends of the said portions being anchored at the ends of the girder.

In the construction shown in Fig. 5, the system is composed of four independent units, two central and two lateral, clamped together at suitable intervals to form a substantially integral structure. Each unit consists of a round head or bar 16 and the lateral web portion 17 the said web portion being radial to the bead or bar. The units are arranged as shown in Fig. 5, the two central units having the portion 16 adjacent and the web portion 17 extending outwardly in the same plane. Each lateral unit is arranged in the same manner asthe adjacent cemral unit, that is, with the bead or bar inwardly and the web outwardly. The units may be held together by any suitable means as for instance, by the straps 18, shown in Fig. 5. Each strap is provided with four transverse grooves 19, and the straps are so arranged with respect to each other, that the grooves of the two straps will register. The straps are held together by means of bolts 20 and nuts 21, the straps and the web of the central units being perforated to permit the passage of the bolts.

It will be noted from an inspection of Fig. 5, that the grooves 19 are not of sufficient depth to entirely receive the bead or bar 16, so that that portion of the strap between the grooves does not contact with the faces of the web 17. It will be evident that precisely the same type of reinforcing structure may be formed from the construction shown in Fig. 5 as from that shown in Fig. 1.

I claim 1. A system of concrete girder reinforcement comprising a structure composed of a central and lateral bars, and webs between the bars and on the outer side of the lateral bars, the cross section of the said central bar and the adjacent webs being equalto the aggregate cross section of the lateral bars and the webs lying at the outer side of the said bars, to permit the lateral bars and the outermost webs to be separated and raised above the level of the central bar and the adjacent webs at the ends of the structure without increasing or diminishing the aggregate amount of metal at any portion of the said structure.

2. A system of concrete girder reinforcement comprising a metallic structure composed of a central and lateral bars and webs between the bars and at the outer side of the lateral bars, said webs being of equal cross section throughout the length of, the structure, and the central bar being of a cross section equal to the aggregate cross section of the lateral bars throughout the length of the structure, to permit the lateral bars and the outermost web to be displaced laterally with respect to the central bar and the adjacent webs without increasing or diminishing the amount of metal in any portion of the length of the bar.

V GROVER O. ROYSE.

Witnesses:

CHARLES E. LITTLE, FREDERICK HEATIL.

Copies of this patent may beobtained for five cents each, by addressing the Commissioner of Patents, Washington, D. 0.) 

